title: Increased hippocampal glutamate and volumetric deficits in unmedicated patients with schizophrenia.
abstract: OBJECTIVE
  Alterations in glutamatergic neurotransmission have been postulated to be a key pathophysiologic mechanism in schizophrenia.
  
  
  OBJECTIVE
  To evaluate hippocampal volumetric measures and neurometabolites in unmedicated patients with schizophrenia and the correlations between these markers. Our a priori hypothesis was that glutamate levels would negatively correlate with hippocampal volume in schizophrenia.
  
  
  METHODS
  Combined 3-T structural magnetic resonance imaging and single-voxel proton magnetic resonance spectroscopy study at the Department of Psychiatry and Behavioral Neurobiology, University of Alabama at Birmingham, of 27 unmedicated patients with schizophrenia and 27 healthy controls.
  
  
  METHODS
  Hippocampal volumetric measures and neurometabolites, and the correlations between volumetric measurements and neurometabolites.
  
  
  RESULTS
  Hippocampal volumetric deficits, increased ratios of hippocampal glutamate and glutamine to creatine (Glx/Cr), and a loss of correlation between hippocampal N-acetylaspartate (NAA)/Cr and Glx/Cr in patients with schizophrenia were found. Significant correlations between hippocampal volumetric measures and Glx/Cr were also found in patients with schizophrenia but not healthy controls.
  
  
  CONCLUSIONS
  Our findings support the theory that alterations in hippocampal glutamate levels potentially account for structural deficits in the hippocampus observed in schizophrenia neuroimaging studies.
authors.affiliation: Departments of Psychiatry and Behavioral Neurobiology and Biomedical Engineering, University of Alabama at Birmingham.
authors.forename: Nina V
authors.initials: NV
authors.lastname: Kraguljac
authors.forename: David M
authors.initials: DM
authors.lastname: White
authors.forename: Meredith A
authors.initials: MA
authors.lastname: Reid
authors.forename: Adrienne C
authors.initials: AC
authors.lastname: Lahti
mesh_terms: D000328:Adult; D001224:Aspartic Acid / Q000031:analogs & derivatives / Q000378:metabolism; D015415:Biomarkers / Q000378:metabolism; D003401:Creatine / Q000378:metabolism; D005260:Female; D018698:Glutamic Acid / Q000378:metabolism*; D005973:Glutamine / Q000378:metabolism; D006624:Hippocampus / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D006859:Hydrogen; D008279:Magnetic Resonance Imaging / Q000295:instrumentation / Q000379:methods*; D009682:Magnetic Resonance Spectroscopy / Q000295:instrumentation / Q000379:methods*; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging / Q000295:instrumentation / Q000379:methods; D012559:Schizophrenia / Q000378:metabolism* / Q000473:pathology; D055815:Young Adult
chemical_list: D015415:Biomarkers; D005973:Glutamine; D001224:Aspartic Acid; D018698:Glutamic Acid; D006859:Hydrogen; C000179:N-acetylaspartate; D003401:Creatine